A Microfluidic 3D Endothelium-on-a-Chip Model to Study Transendothelial Migration of T Cells in Health and Disease

The recruitment of T cells is a crucial component in the inflammatory cascade of the body. The process involves the transport of T cells through the vascular system and their stable arrest to vessel walls at the site of inflammation, followed by extravasation and subsequent infiltration into tissue. Here, we describe an assay to study 3D T cell dynamics under flow in real time using a high-throughput, artificial membrane-free microfluidic platform that allows unimpeded extravasation of T cells. We show that primary human T cells adhere to endothelial vessel walls upon perfusion of microvessels and can be stimulated to undergo transendothelial migration (TEM) by TNFα-mediated vascular inflammation and the presence of CXCL12 gradients or ECM-embedded melanoma cells. Notably, migratory behavior was found to differ depending on T cell activation states. The assay is unique in its comprehensiveness for modelling T cell trafficking, arrest, extravasation and migration, all in one system, combined with its throughput, quality of imaging and ease of use. We envision routine use of this assay to study immunological processes and expect it to spur research in the fields of immunological disorders, immuno-oncology and the development of novel immunotherapeutics.     

Histological Evaluation and Gene Expression Profiling of Autophagy-Related Genes for Cartilage of Young and Senescent Rats

Autophagy is a cellular mechanism that protects cells from stress by digesting non-functional cellular components. In the cartilage, chondrocytes depend on autophagy as a principal mechanism to maintain cellular homeostasis. This protective role diminishes prior to the structural damage that normally occurs during aging. Considering that aging is the main risk factor for osteoarthritis, evaluating the expression of genes associated with autophagy in senescent cartilage might allow for the identification of potential therapeutic targets for treatment. Thus, we studied two groups of young and senescent rats. A histological analysis of cartilage and gene expression quantification for autophagy-related genes were performed. In aged cartilage, morphological changes were observed, such as an increase in cartilage degeneration as measured by the modified Mankin score, a decrease in the number of chondrocytes and collagen II (Col2a1), and an increase in matrix metalloproteinase 13 (Mmp13). Moreover, 84 genes associated with autophagy were evaluated by a PCR array analysis, and 15 of them were found to be significantly decreased with aging. Furthermore, an in silico analysis based on by two different bioinformatics software tools revealed that several processes including cellular homeostasis, autophagosome assembly, and aging—as well as several biological pathways such as autophagy, insulin-like growth factor 1 (IGF-1) signaling, PI3K (phosphoinositide 3-kinase)/AKT (serine/threonine kinase) signaling, and mammalian target of rapamycin (mTOR) signaling—were enriched. In conclusion, the analysis identified some potential targets for osteoarthritis treatment that would allow for the development of new therapeutic strategies for this chronic disease.     

Study of the Degradation Effects on Aged Wood Beams from the Cathedral of Morelia,Mexico by Acoustic Birefringence Measurements

Russian Journal of Nondestructive Testing - The present study investigates the influence of degradation effects due to natural aging of wood beams from the Cathedral of Morelia, Mexico by using...     

Virus-Based Nanoreactors with GALT Activity for Classic Galactosemia Therapy

Enzymatic nanoreactors were obtained by galactose-1-phosphate uridylyl-transferase (GALT) encapsulation into plant virus capsids by a molecular self-assembly strategy. The aim of this work was to produce virus-like nanoparticles containing GALT for an enzyme-replacement therapy for classic galactosemia. The encapsulation efficiency and the catalytic constants of bio-nanoreactors were determined by using different GALT and virus coat protein ratios. The substrate affinity of nanoreactors was slightly lower than that of the free enzyme; the activity rate was 16 % of the GALT free enzyme. The enzymatic nanoreactors without functionalization were internalized into different cell lines including fibroblast and kidney cells, but especially into hepatocytes. The enzymatic nanoreactors are an innovative enzyme preparation with potential use for the treatment of classic galactosemia.     

Vibrational properties and infrared dielectric features of Gd2CoMnO6 and Y2CoMnO6 double perovskites

Gd₂CoMnO₆ and Y₂CoMnO₆ double perovskite ceramics were obtained from the polymeric precursors method and investigated by X-ray diffraction, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), Raman and Fourier Transform Infrared (FTIR) spectroscopies. Our results show that these samples present similar structural and vibrational characteristics that are fully compatible with a monoclinic structure belonging to the P2₁/n space group, with ordered Co²⁺ and Mn⁴⁺ cations. Infrared-reflectivity spectroscopy was employed to investigate the polar phonon features and to determine the intrinsic dielectric response of the materials. In particular, the extrapolated dielectric constants at the lower frequency infrared limit showed to be independent on the particle size, and were determined as ${\epsilon \prime }_{\mathit{intr}}\approx 17.8$ and 16.0, for Gd₂CoMnO₆ and Y₂CoMnO₆, respectively. Otherwise, it is shown that for smaller RE radius the FTIR bands become more evidenced, due to a higher octahedral rotation and lower $<$Co-O-Mn$>$ angle into the distorted monoclinic structure.     

Functionalized-radiolabeled hydroxyapatite/tenorite nanoparticles as theranostic agents for osteosarcoma

Hydroxyapatite (HA) nanoparticles (NPs) doped with different radioisotopes for use as theranostic systems play an important role in scientific research nowadays due to their ability to simultaneously act in the treatment and diagnosis of various types of cancers. In this work, we describe the synthesis and characterization of a hydroxyapatite/tenorite nanocomposite functionalized with folic acid, representing a nanotheranostic material with potential for application as an agent in positron emission tomography imaging systems and to act specifically in the treatment and diagnosis of osteosarcoma. ⁶⁴Cu and ³²P were produced by nuclear activation in the TRIGA reactor at CDTN. The obtained samples were characterized by XRD with Rietveld refinement, XAFS, SEM, BET, TGA, FTIR, CHN, ICP-AES, XPS and gamma spectroscopy. We investigated how CuO grows in HA NPs, the stability of the interactions between CuO and HA constituents and the interactions between folic acid and the surface of the HA NPs. The results indicate the formation of a second phase (tenorite) besides hydroxyapatite, and that the interactions between the two phases are stable, resulting in a nanocomposite. Furthermore, the activation of ⁶⁴Cu and ³²P inside the HA matrix, through the exposition to a neutron flux, produces a theranostic material of interest for biological tests.     

Preparation,thermal and mechanical properties of poly (ether-imide) composite reinforced with carbon nanotube buckypaper

Vacuum filtration technique was employed in order to prepare multiwalled carbon nanotube buckypapers (MWCNT-BP) through a well-dispersed suspension of MWCNT/H₂O with the aid of Triton X-100 surfactant. The obtained BP (buckypaper) was then infiltrated with a solution of poly (ether-imide) (PEI) under vacuum conditions. The visual inspection demonstrated the importance of the centrifugation procedure before the vacuum filtration of the suspension, revealing a smooth surface of the as-prepared buckypaper. Thermogravimetric experiments (TGA) and scanning electron microscopy analyses have demonstrated the role of isopropyl alcohol in the removal of Triton X-100 from the nanotube network. SEM observations of the cross-section view of the samples revealed a porous network of the fabricated BP, and an impregnated structure of the PEI/BP composite, suggesting a good interfacial bonding between MWCNT and PEI. Moreover, significant improvements were achieved in mechanical and thermal properties of PEI matrix by the incorporation of BP, as the increase of both the storage modulus (42%) and the T _g (11 °C) for the PEI/BP composite. TGA have shown a significant increase in the onset decomposition temperature of the polymer by the incorporation of the BP. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48330.     

Radiomics and Machine Learning in Oral Healthcare

The increasing storage of information, data, and forms of knowledge has led to the development of new technologies that can help to accomplish complex tasks in different areas, such as in dentistry. In this context, the role of computational methods, such as radiomics and Artificial Intelligence (AI) applications, has been progressing remarkably for dentomaxillofacial radiology (DMFR). These tools bring new perspectives for diagnosis, classification, and prediction of oral diseases, treatment planning, and for the evaluation and prediction of outcomes, minimizing the possibilities of human errors. A comprehensive review of the state‐of‐the‐art of using radiomics and machine learning (ML) for imaging in oral healthcare is presented in this paper. Although the number of published studies is still relatively low, the preliminary results are very promising and in a near future, an augmented dentomaxillofacial radiology (ADMFR) will combine the use of radiomics‐based and AI‐based analyses with the radiologist's evaluation. In addition to the opportunities and possibilities, some challenges and limitations have also been discussed for further investigations.